JPH03202277A - Cutter, grinder and polisher using composite diamond abrasive - Google Patents

Abstract

PURPOSE:To obtain a tool having excellent cutting, grinding and polishing capabilities by longitudinally orientating composite diamond abrasive particles on a surface to be ground. CONSTITUTION:A tool is composed of a cutting, grinding and polishing member consisting of compound abrasive particles 1 having a ratio of a maximum major- axial length to alumina minor-axial length that is at least 1.2, and coated over its entire surface made of heat-resistant particulate materials with gas-phase diamond film and a binder 2, and a support member (base fabric) 3. In this case, the composite diamond particles 1 are orientated longitudinally of a surface to be ground.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is directed to cutting, grinding, cutting, grinding, and polishing using composite diamond grains, in which diamonds are precipitated on the surface of heat-resistant grains by a vapor phase method, as an abrasive body. Regarding polishing tools.

<Prior Art> Conventionally used cutting, grinding, and polishing tools using diamond particles include metal bond wheels, resin bond wheels, vitrified bond wheels, and coated abrasive paper. However, the diamond grains used are mainly natural or artificial (ultra-high pressure) grains with a long-width ratio of less than 1.2. These are expensive and have limited fields of application. The applicant of the present application previously invented and filed a patent application No. 219889/1989 for a heat-resistant granule whose surface is coated with vapor-grown diamond. However, these particles had a spherical shape or a spherical shape in terms of the length/breadth axis ratio.

<Problems to be Solved by the Invention> The conventionally used tools using diamond grains had low cutting, grinding, and polishing efficiency as shown below.

That is, the length ratio is low and the bondability is low. For example, in resin bond systems, protrusions are formed by surface treatment to compensate for the bondability. On the other hand, in the field of coated abrasive papers, those using diamond grains have been extremely limited due to cost and low bonding properties.

Conventionally, abrasive grains such as AbOs and Sic have been generally used. However, these materials did not have high cutting performance and cost performance.

Therefore, from a practical standpoint, there has been a demand for the development of cutting, grinding, and polishing tools that have both high cutting performance and cost performance.

An object of the present invention is to provide a tool capable of cutting, grinding, and polishing that meets the above-mentioned requirements.

<Means for Solving the Problem> In order to achieve the above object, the inventor of the present invention, as a result of intensive research, has found that all heat-resistant granules having a ratio of the longest axis length to the shortest axis length are at least 1.2. The composite diamond grains obtained by precipitating microcrystalline diamond grains on the surface using a vapor phase method are oriented in a specific direction so that the cut surface is in vertical contact with the tool.High efficiency cutting, grinding, and polishing are possible. They have discovered that this is the case and have completed the present invention.

That is, the present invention provides a cutting method comprising composite diamond grains whose entire surface is coated with a vapor-grown diamond film and whose ratio of longest axis length to shortest axis length is at least 1.2, and a binder. The present invention relates to a cutting, grinding, and polishing tool using composite diamond grains, which comprises a grinding, polishing body and a support body, and the composite diamond grains are arranged vertically with respect to the surface to be cut.

The present invention will be explained in detail below.

The heat-resistant granules used in the present invention include diamond, W, Mo, Ta, WC, SiC, and TiC1T.
aC, AjzOs, Zr0z, CrzOs, Ta
N, ZrN.

Heat-resistant metals and ceramics such as Si3N4 are suitable.

As mentioned above, it is necessary for the grain shape to have a ratio of the longest axis length to the shortest axis length of at least 1.2, but practically it is desirable that the ratio is 1.5 to 10, especially 5 or around it is preferable. The reason for this is that by providing orientation, high bonding strength and long tool life are possible. Further, the shortest axis length needs to be 10 to 700 μm, and particularly preferably in the range of 30 to 400 μm.

How to make the base grains: (1) For ceramics and heat-resistant metal ingots, pulverized grains are sieved and sorted. That is, it is sufficient to classify the material using a sieve whose mesh is finer than its major diameter, and to classify what remains on the sieve through a sieve whose diameter is coarser than its minor diameter, and to use the material under the sieve.

(2) A product with a large length/breadth axis ratio is obtained by powder sintering. For example, a method may be used in which the unfired body is made into a thin plate shape, crushed to prepare flat grains, and then fired in a rotary kiln or the like.

The surface of the heat-resistant granules of the diamond composite grains used in the cutting, grinding, and polishing tools of the present invention is coated with polycrystalline diamond by a vapor phase method. The desired thickness of the coating varies depending on the size of the heat-resistant granules, and is determined in consideration of the application, the time required for coating, etc.

The particle size constituting the diamond coating layer can be selected from fine particles on the order of submicrons to about 20 μm depending on the precipitation synthesis conditions.

Diamond particles can be deposited on the surface of the heat-resistant granules by applying a known vapor phase diamond synthesis method. That is, raw material gases include hydrocarbons such as methane, ethane, propane, benzene, toluene, and cyclohexane, oxygen-containing organic compounds such as methanol, ethanol, propatool, tertiary-butanol, and acetone, and furthermore, H2O, CO□, and CO. It is also possible to use a material to which an oxygen-containing substance such as the like is added. These gases may be used alone or in combination with a carrier gas such as hydrogen or argon. The gas pressure is about 10-2 orr,
Depending on the synthesis method, it is possible to create a pressurized state.

In order to precipitate diamond particles on the entire surface of heat-resistant granules using these methods, raw materials for diamond synthesis are present, and the granules are placed in a heat-resistant container in an atmosphere excited to a state capable of producing diamonds. A method such as placing the particulate matter in a position that will become a reaction space region and intermittently inverting the particulate matter using a vibrator or the like connected to a heat-resistant container may be used.

Although the granules partially overlap with neighboring granules, the thickness of the diamond precipitation on the major diameter surface is larger than that on the minor diameter surface and is film-like, and the entire deposition surface is irregularly uneven.

Since heat-resistant granules are made by pulverization or the like, they have many active sites. These active sites act as nuclei for diamond formation, and diamond particles are precipitated.

The cutting, grinding, and polishing tool of the present invention is composed of a cutting, grinding, and polishing body made by mixing and solidifying the composite diamond grains with a binder, and a support that supports the cutting, grinding, and polishing body.

Next, specific examples of the cutting, grinding, and polishing tool of the present invention will be explained based on the drawings.

FIG. 1 shows a coated abrasive paper with composite diamond grains arranged vertically on the backing paper. In the figure, 1 is a composite diamond grain, 2 is a binder, and 3 is a backing paper. The cutting, grinding, and polishing tools shown in the drawing are made by uniformly distributing composite diamond grains onto a cloth tape, for example, and placing it in a charged state. Due to the high insulating properties of diamond, the composite diamond grains are placed on a backing paper as shown in the figure. On the other hand, in the vertical direction, in the figure, f
arranged vertically. To fix this to a backing paper, for example, place a backing paper thinly coated with a binder facing down, place the composite grains below, and apply an electric field between the backing paper and the composite grains. Attach to. Thereafter, the fixing agent is solidified to fix the grains.

FIG. 2 relates to a metal bond wheel which is another practical example of the cutting, grinding, and polishing tool of the present invention.

In the figure, 11 is a diamond composite powder, 12 is a metal bond, and 13 is an alloy.

This metal bond wheel mixes composite diamond particles and metal bond (e.g. copper powder and bronze powder),
When cold pressed onto an annular base metal, the composite diamond grains are oriented perpendicular to the compression direction. This material is further subjected to the processing steps of firing, hot pressing, truing, and dressing to form a metal bond wheel. Incidentally, as the support, a support having a cylindrical shape or a cup shape can also be used.

Next, the present invention will be explained with reference to Examples and Comparative Examples.

Example 500 mg of alumina grains having an average longest axis length of 650 μm and an average shortest axis length of 80 μm were set in a reaction packet in a hot filament diamond synthesis apparatus. As the excitation hot filament, a 0.3 mmφ tank wire processed into a coil shape was used, and it was placed 7 mm from the inner bottom of the reaction packet.
It was set to a height of . During synthesis, 10 packets are generated every 10 minutes.
Intermittent vibration was performed using an electromagnetic vibrator at a rate of seconds.

The synthesis reaction was carried out at a pressure of 100 Torr, a tantalum filament temperature of 2450°C, a raw material gas of ethanol and hydrogen, an ethanol concentration of 3% by volume, and a total flow rate of 150.
The test was carried out at cc/min for 10 hours.

After the reaction was completed, the particles were removed from the packet and their surface condition was observed using an optical microscope. The surface was covered with a densely structured film consisting of diamond particles of several μm in size. Particularly on the longest diameter surface of the film, irregular unevenness with steps of about 10 μm was observed. In addition, when we measured the Raman shift of the particle surface by micro-Raman spectroscopy, we found a sharp peak due to diamond bonding at 1334 cm'' and a very broad and low peak around 1500 cm'', indicating that a trace amount of i in the diamond phase. It was confirmed that it was a diamond coating film containing a carbon component.The weight of the obtained diamond composite powder was 890 mg.

Next, using this composite grain, a metal bond diamond wheel of 180 mmφ was made as shown below. Diameter 1
Using the composite grain 600B, 20g of copper powder as metal bond, 14g of bronze powder etc. on a 74mmφ iron base metal,
A metal bond wheel with composite powder oriented as shown in FIG. 1 was prepared by cold pressing, baking, hot press truing, and dressing.

Next, a d-type cutting test was conducted using this diamond wheel. The work material is marble block (100x 20x
35mm), 20X 35mm surface 280Or,
Cutting was performed 10 times using P and M cutting machines. At that time, the initial power was 270 W, the average power was 310 W, and the average cutting time per cut was 140 seconds. After cutting 10 times, the surface composed of the composite powder and metal bond, that is, the abrasive grain surface, was observed using an optical microscope. The results showed that 70% of the composite powder remained, 20% was crushed, and 10% fell off.

Comparative example Average diameter of fused alumina with a length ratio of 1.1 or less 300 μm
Composite diamond grains were produced using the same conditions as in the examples. The production amount was 910 mg. As a result of microscopic observation, the surface of the composite diamond grains was covered with a dense diamond film of several micrometers, similar to the example.

The results of microscopic Raman spectroscopy were also almost the same as those of the composite diamond grains in Examples. 600mg of this composite powder
A diamond wheel with a diameter of 180 mm was used to conduct a wet cutting test in the same manner as in the examples. The initial power at that time was 300 W, the average power was 350 W, and the cutting time per cut was 150 seconds. Observation results using an optical microscope after cutting 10 times showed that 55% of the composite powder remained and 2% of the composite powder remained.
5% were crushed and 20% had fallen off.

The molten alumina used in the comparative example with an average grain size of 300 μm and having a length ratio of 1.1 or less had the same volume as the alumina grains used in the example, but had a surface area of about 56%.
It becomes.

Comparing the marble block cutting test characteristic values of metal bonded diamond wheels in Examples and Comparative Examples, both Examples are superior.

That is, the initial power and average power were low, and the average cutting time per cycle was short. Furthermore, in the case of the abrasive grain surface after cutting 10 times, the amount of crushing and falling off was smaller in the case of the example than in the comparative example.

The Examples and Comparative Examples are examples of metal-bonded diamond wheels. For example, diamonds are deposited on heat-resistant granules having a ratio of the longest axis length to the shortest axis length of at least 1.2 by resin bonding on a backing paper. Even in the cutting, grinding, and polishing tool shown in Fig. 1 in which the composite diamond grains are oriented and fixed in the direction f perpendicular to the backing paper, the polishing efficiency is superior to that in the case where the composite diamond grains are not oriented. I'm there.

The reason is that the composite diamond grains used on the abrasive grain surface are
The material used in the present invention has a long and slender shape, and the contact resistance between the workpieces is small when ground compared to the comparative example with a low long-to-short diameter ratio, which is noticeable due to the self-synthesizing effect of the composite powder. This is because it is hard to get clogged, has a strong bonding force due to its anchoring effect, and lasts for a long time.

<Effects of the Invention> Compared to conventional metal-bonded diamond wheels and coated abrasive paper coated with diamond grains, the cutting, grinding, and
Abrasive tools have excellent cutting, grinding, and polishing abilities, and are of great practical value.

[Brief explanation of drawings]

FIG. 1 shows a cutting, grinding, and polishing tool of the present invention in which diamond composite powder with an elongated particle size is fixed to a backing paper using an adhesive. Figure 2 shows a metal bond wheel of the present invention made using diamond composite powder with an elongated particle size. In the figure, 1, 11... Diamond composite powder, 2... Binder, 3... Backing paper, 12... Metal bond, 13
...Indicates the base metal.

Claims (3)

[Claims] (1) (A) Heat-resistant granules consisting of composite diamond grains whose entire surface is coated with a vapor-grown diamond film and whose ratio of longest axis length to shortest axis length is at least 1.2, and a binder. A cutting, grinding, and abrasive tool using composite diamond grains, comprising a cutting, grinding, and abrasive body; and (b) a support body, the composite diamond grains being oriented vertically with respect to the surface to be cut. . (2) The cutting, grinding, and polishing tool using composite diamond grains according to claim (1), wherein the cutting, grinding, and polishing body is fixed to a circular support to form a wheel. (3) The cutting, grinding, and polishing tool using composite diamond grains according to claim (1), wherein the support is a paper mount and the binder is a resin bond.